Octadecahedron

There are 107,854,282,197,058 topologically distinct convex octadecahedra, excluding mirror images, having at least 11 vertices.

[2] (Two polyhedra are "topologically distinct" if they have intrinsically different arrangements of faces and vertices, such that it is impossible to distort one into the other simply by changing the lengths of edges or the angles between edges or faces.)

The most familiar octadecahedra are the heptadecagonal pyramid, hexadecagonal prism, and the octagonal antiprism.

The hexadecagonal prism and the octagonal antiprism are uniform polyhedra, with regular bases and square or equilateral triangular sides.

Among near-miss Johnson solids, the chamfered cube is one notable non-uniform octadecahedron.

Ball-and-stick model of the octadecahedral closo -undecaborate ion, [B 11 H 11 ] 2− , as found in the crystal structure of the benzyltriethylammonium salt. [ 1 ]